Friday, October 31, 2014

Presocratic themes

I.  The earliest philosophers of ancient Greece were the first thinkers in the Western tradition to pose fundamental questions regarding the nature of the universe, together with the reliability - or not - of our efforts to ascertain this knowledge.  In their work they showed that both empirical observation and reasoning were necessary, though the balance differed from one thinker to another.
Modern studies of ancient Greece’s earliest philosophers focused initially on issues of nomenclature and periodization.  Here the pivotal figure was Socrates.  Did his appearance signal a new departure, relegating his predecessors to a superseded phase of thought?  That idea goes back at least as far as Cicero, who held that Socrates had achieved an epochal advance by bringing philosophy down from the heavens to the world of humanity (Tusculan Disputations, prologue to book 5).  Or was Socrates the last of the early philosophers, leaving Plato to enjoy the honor of initiating the new era?
In 1788 the Berlin Lutheran pastor Johann Augustus Eberhard introduced the expression “die Vorsokratiker” (the Presocratics) in his Allgemeine Geschichte der Philosophie. In this usage he was followed by his famous pupil Friedrich Schleiermacher, who was inspired to produce a study of  one of the major figures: “ Herakleitos der dunkle von Ephesos: dargestellt aus den Trümmern seines Werkes und den Zeugnissen der Alten”  (1807). 
A different interpretation was advanced by Wilhelm Traugott Krug, who in his 1815 Geschichte der Philosophie alter Zeit presented Socrates as the concluding figure of his first chapter, starting a new chapter with Plato.  The new approach appeared in the title of a Latin series by the Dutch philologist Simon Karsten, Philosophorum Graecorum Veterum praesertim qui ante platonem Floruerunt operum Reliquiae (1830-38).  Finally, in 1872 Friedrich Nietzsche offered a series of lectures on “Pre-Platonic Philosophy.”  Never published in the author’s lifetime, these lectures have been reconstructed in modern editions, based on the philosopher’s notes (see, Friedrich Nietzsche, The Pre-Platonic Philosophers, Urbana and Chicago, 2000). 
Nietzsche’s approach has been revived from time to time.  Among its advantages is that it addresses the anomaly of classifying Leucippus and his pupil Democritus as “pre-Socratic,” when they were in fact contemporaries of Socrates.  However, the difficulty does not disappear entirely, in as much as Democritus is supposed to have died ca. 370 BCE.  Plato seems to have begun composing his dialogues shortly after the death of Socrates in 399, so that some overlap persists.
At all events, Nietzsche’s approach did not prevail.  In fact it was already becoming sidelined in his own time as a result of Eduard Zeller’s influential Die Philosophie der Griechen in ihrer geschichtliche Entwicklung (first edition, 1844-52, with several enlargements in subsequent years).  Zeller’s preference was for the Presocratic concept.  His choice was duly ratified by the standard work of Hermann Diels, Die Fragmente der Vorsokratiker, with the first edition appearing in 1903 (again revised and reprinted several times).
According to the Oxford English Dictionary, the term “Pre-Socratic” was introduced into English in 1871 by Alexander Campbell Fraser in his Life and Letters of George Berkeley.
Recently, the distinguished Swiss philologist Walter Burkert has stated his preference for “Preplatonics” (n his contribution to P. Curd and D. W. Graham, eds., The Oxford Handbook of Presocratic Phllosophy, 2008, p. 55).  He does not seem to have been widely followed.
As we have seen, the arguments for this preference are significant.  Should one adopt it?  Probably not, because the the term "Presocratic" has become fixed.  After all, we still speak of Gothic architecture, even though we know that it was not created by the Goths; and of the West Indies, even though they are not located in India.

II.   BEFORE THALES

1. Orpheus and Orphism.  
In ancient Greece Orpheus was a legendary musician, poet, and prophet.  He was noted for his magical ability to enchant all things with his music.  Poets such as Simonides of Ceos claimed that Orpheus's music and singing could charm the birds, fish. and wild beasts, coax the trees and rocks into dance, and even divert the course of rivers.  The most poignant episode of his career was his failed attempt to retrieve his wife, Eurydice from the underworld.  After this loss he renounced the love of women.  According to Ovid and other sources, his death came at the hands of Thracian women who were angry at his abandonment of heterosexuality and his efforts to seduce their husbands.  Because of this last phase of his career, Orpheus was sometimes regarded in antiquity as the founder of the institution of pederasty.
As an archetype of the inspired singer and poet, Orpheus ranks one of the most significant figures in the spread of classical mythology in Western culture, figuring in countless works of art and popular culture in several media, including poetry, film, opera, and painting.

For the Greeks, Orpheus was a founder and prophet of the “Orphic mysteries.”  He was credited with the composition of the Orphic Hymns. Shrines containing purported relics of Orpheus were venerated as oracles.  Because of the story of Orpheus’s descent into Hades, the Orphic tradition is associated with death, and with Persephone, who annually descended into the Underworld and then returned. Orpheus was sometimes honored as the inventor of the Mysteries of Dionysus.

The earliest literary reference to Orpheus is a two-word fragment of the sixth-century-BCE lyric poet Ibycus: onomaklyton Orphēn ("Orpheus famous-of-name"). Neither Homer nor Hesiod mentions him.  The fifth century BCE offers more abundant evidence of distinctly Orphic beliefs, including graffiti."  Classical sources, such as Plato, refer to "Orpheus-initiators" (Ὀρφεοτελεσταί), and rites associated with them, although how far "Orphic" literature in general related to these rites is not certain.  As in the Eleusinian mysteries, initiation into Orphic rites promised advantages in the afterlife.

Differing from popular ancient Greek religion, Orphism showed the following main features.  This faith (as it probably should be called) regarded human souls as divine and immortal, though destined to live (for a period) in a "grievous circle" of successive bodily lives through metempsychosis or the transmigration of souls. Orphism prescribed an ascetic way of life which, together with secret initiation rites, was supposed to guarantee not only eventual release from the "grievous circle" but also communion with gods. Finally, it possessed sacred texts relating the origin of the gods and human beings.

Distinctively Orphic views and practices are attested as early as the works of Herodotus, Euripides, and Plato. Found in 1962 and recently published, the Derveni papyrus offers evidence of the Orphic theology dating back to the fourth century BCE, and it is probably even before.  Inscriptions found in various parts of the Greek world attest the early existence of a movement with the core beliefs associated with the name of Orphism.

The Orphic theogonies are genealogical works similar to Theogony of the poet Hesiod, but the details are different. They may reflect the influence of Near Eastern models. The main narrative is as follows.  Dionysus (in his incarnation Zagreus) is the son of Zeus and Persephone. Zeus gives his inheritance of the throne to the child.  The Titans are enraged over the proclamation of attendance and under Hera's instigation decide to murder the child, The Titans then beguile Dionysus with a mirror and children's toys; they then murder and devour him. Yet Athena saves the heart and relates the crime to Zeus who in turn hurls a thunderbolt at the Titans. The resulting soot, from which sinful mankind is born, contains the bodies of the Titans and Dionysus. The soul of man (the Dionysus factor) is therefore divine, while the body (then Titan factor) holds the soul in bondage. Thus it was declared that the soul returns to a host ten times, bound to the wheel of rebirth.

There are two Orphic stories of the rebirth of Dionysus.  In one of them the heart of Dionysus is implanted into the thigh of Zeus.  In the other he has impregnated the mortal woman Semele,resulting in Dionysus's literal rebirth. 

We have evidence of several Orphic scriptures.  One is the "Protogonos Theogony," lost, composed ca. 500 BCE; it is known through the commentary in the Derveni papyrus, and references in classical authors (Empedocles and Pindar).The "Eudemian Theogony," is also lost: composed in the fifth century BCE, it stems from a syncretic Bacchic-Koureetic cult. The "Rhapsodic Theogony," also lost, was composed in Hellenistic times, incorporating earlier works. It is known through summaries in later neo-Platonist writers.  Finally, the Orphic Hymns are 87 hexametric  poems of a shorter length composed in the late Hellenistic or early Roman period.

Gold-leaf tablets found in graves at various sites coming from the fourth century BCE and after) give instructions to the dead. Although these thin tablets are often highly fragmentary, collectively they present a consistent account of the passage into the afterlife. When the deceased arrives in the underworld, he is expected to confront obstacles. He must take care not to drink of Lethe ("Forgetfulness"), but to imbibe at the pool of Mnemosyne ("Memory"). The initiate is provided with formulaic expressions with which to present himself to the guardians of the afterlife.

A number of texts from Pindar, Empedocles, Heraclitus, Euripides, and Plato seem to show the influence of Orphic ideas about the nature and fate of soul. There are particular affinities with the salvationary aspects of Pythagoreanism.

Some modern scholars have expressed doubt that there was any single unified Orphic doctrine. Instead, different Orphic texts and practitioners propounded various and often conflicting ideas about the origin, metaphysics, physics, and fate of the soul. In this revisionist view, the ideas expressed in some of these texts seem hard to square with the idea that transmigration and the immortality of the individual soul figures as a permanent and central doctrine of Orphism. It may be that different Orphic texts reflect overlapping but divergent conceptions of salvation, founded on divergent conceptions of the soul.

Orphic concepts and practices show parallels with elements of Pythagoreanism.  As yet, though, there is too little evidence to determine the extent to which one movement may have influenced the other.

Mentioned above, the Derveni papyrus ranks as the most substantial papyrus to have been found on Greek soil. It, and is dated roughly between 340 and 320 B.C. The name derives from the site where it was discovered, some six miles north of the city of Thessaloniki, in whose Archaeological Museum it is now preserved. It was found in a tomb among the remnants of a funeral pyre.  Once the material was recovered, scholars faced the exacting task of unrolling and separating the layers of the charred papyrus roll, and then of joining the numerous fragments together again.  As a result, 26 columns of text were recovered, all with their bottom parts missing, as they had perished on the pyre.
The book, which seems to have been compiled toward the end of the fifth century BCE, purports to contain the eschatological teaching of a mantis or inspired prophet.  The content is divided between religious instructions pertaining to sacrifices to gods and souls, and allegorical commentary on a theogonic  poem ascribed to Orpheus. 
The author’s outlook is philosophical, displaying, in particular, a physical system recalling those of Anaxagoras, the Atomists, and Diogenes of Apollonia. His allegorical method of interpretation is sometimes reminiscent of Socrates’ playful mental and etymological  acrobatics as seen in Plato’s Cratylus. The authorship is a matter of  dispute among scholars; it will probably never be known. 

2. Hesiod.  The poet Hesiod is generally thought by scholars to have been active between 750 and 650 BCE, about the same time as Homer.  His is the first European poetry in which the poet regards himself as a topic, an individual with a distinctive role to play  Ancient authors credited him and Homer, perhaps somewhat extravagantly, with establishing Greek religious customs. Modern scholars consult Hesiod as a major source for Greek mythology, legendary history, farming techniques, early economic thought, and ancient time-keeping.

Hesiod’s Theogony addresses the origins of the world (cosmogony) and of the gods (theogony).  Cosmogony is of course an interest he shared with the Presocratic thinkers, though they were generally dismissive of his florid polytheism. 

The creation myth in Hesiod has long been held to show Eastern influences, such as the Hittite Song of Kumarbi and the Babylonian poem known as the Emuma Elish.   In all likelihood, the setting for this cultural crossover was the eighth- and ninth-century Greek trading colonies such as Al Mina in North Syria. 

3.  Connections with the ancient Near East and Egypt.  

Initially the Greeks came into contact with the Western fringes of the ancient civilization of the Middle East in Phoenicia in the Levant and on the Western coast of Anatolia, a region where the Hittite Empire had once flourished.  Gradually, however, they became aware of the centrality of Mesopotamia, the site of one of the oldest civilizations in the world.  Here, in the fourth millennium BCE the Sumerians developed the first city states, using cuneiform writings for record keeping and also to preserve religious and poetic texts.  The Sumerian language has no known relatives.  People in the northern part of Mesopotamia, known as Akkad, spoke a Semitic language related to Canaanite and Hebrew.
Babylonia emerged when Hammurabi (flourished ca. 1728–1686 BCE) created a large realm by unifying the territories of Sumer and Akkad.  Together with the related people, the Assyrians, the Babylonian rulers cultivated scientific observation, especially in the field of astronomy.  Later, the Greeks were to benefit from this accumulation of knowledge.
In due course, the Neo-Babylonian Empire arose, lasting from the revolt of Nabopalassar in 626 in BCE. The empire was conquered by the Persian ruler Cyrus the Great in 539 BCE.  Gradually, under the Achaemenid dynasty the Persians extended their power westwards, extending their sway over the Greek cities of Ionia on the western coast of Anatolia.  While the Persians failed to conquer continental Greece, this period saw a great deal of cultural interchange.  At the height of its power, the Achaemenid dynasty encompassed approximately 8.0 million square kilometers, held the greatest percentage of world population to date, and territorially ranked the largest empire of classical antiquity.
The connections linking Greece with pharaonic Egypt were less dramatic.  Still, Greeks traveled there as traders and also in some cases for learning as well.  
A commonplace theme in cultural history is that, with the Presocratic thinkers the Greeks made a crucial transition from mythos to logos.  The first was associated with the venerable realms of the ancient Near East and Egypt, the latter being incarnated in the Greek Enlightenment. The two, it is held are fundamentally different and irreconcilable.
All the same, it is reasonable to ask whether it may not be the two modes are not so different as usually supposed, and that early Greek thought owes a debt to its eastern and southern neighbors.  This research has been spurred by the extensive finds and translation of the cuneiform literature that began in the middle of the nineteenth century.

The older civilizations cherished a genre of wisdom literature, consisting of proverbial sayings and pithy observations, generally pertaining to ethical and other issues of daily life. These texts are found in both the ancient Nr East and Egypt.  They are also represented in some books of the Hebrew Bible, such as Proverbs and the Wisdom of Solomon.  This tradition surely lies behind the tendency of some Presocratics such as Heraclitus and Empedocles to present key ideas in the form of short, gnomic sayings.

Another area of legacy is represented by the accounts of creation found in the older civilizations.   In Egypt, for example, there is the Memphite theology; in Mesopotamia, the Enuma Elish.

There are also scientific elements, such as the astronomical observations of the Babylonians.  The “Pythagorean theorem” was actually first discovered by the Egyptians.  Significantly, Pythagoras is supposed to have traveled to Egypt.

Finally, one should note the somewhat speculative theory of E. R. Dodds, to the effect that Eurasian shamanism contributed to the mantic or prophetic tradition of ancient Greece.

III.  SOURCES
Unfortunately not one complete work survives from the writings of the Presocratic philosophers. Only fragments of their own utterances. together with reports and testimonies of their theories have come down to us.  
While Plato alludes to Presocratic thinkers, especially Parmenides, he uses them for his own purposes and cannot be relied on as a basic source.  Matters are quite different withs his successor Aristotle, who discusses some of them in detail, though some aspects of the veracity of his account have been questioned by modern scholars.  Still, his interest fostered further observations and quotations from his followers and commentators. There has also been interest on the part of Neoplatonic writers and even among some early Christian authors, such as Clement of Alexandria. 
In some instances, these writers seem to have access to complete treatises by the Neoplatonics - treatises that were subsequently lost.  In other cases they seem to have borrowed from anthologies consisting of techniques deemed by the compiler to have been representative.
Over the course of several generations, modern scholarship has carefully sifted these sources in order to reconstruct Presocratic thought. The following discussion outlines the main sources that have been exploited to mine the Presocratic fragments and testimonies.
Aristotle (384-322 BCE) terms them “investigators of nature” (physiologoi), tacitly backing the notion that Socrates had achieved a revolution in thought by bringing philosophy down from the heavens to the human world.  His discussions appear in his Physics and Metaphysics (most notably), as well as in On the Heavens and On the Soul.  In an influential monograph of 1935, Harold Cherniss argued that Aristotle had persistently distorted the views of the Presocratics because he analyzed them for the purposes of his own arguments.  More recently, a balanced approach has emerged in which Aristotle is perceived as presenting a consistently evolutionary theory of thought, whereby the Presocratics take honored places as precursors.
The Opinions of the Physicists by Aristotle’s pupil Theophrastus (ca. 371-ca. 287) also contains some useful material. 
The somewhat mysterious Aetius (second or first century BCE) created a book in 130 chapters containing opinions of many thinkers, reduced to a sort of capsule form.  The contents of his work have been partially reconstructed from other sources.
Diogenes Laertius (early to middle third century CE) takes a biographical approach.  His accounts figure significantly in the testimonia section of the sources.
A good deal of information can be gleaned from the prolific work of Plutarch (ca. 50-120 CE).
Some other bits can be found in the early Christian writers Clement of Alexandria, Hippolytus, and Eusebius.
Finally, the commentaries of Simplicius (sixth century CE) offer useful material.
All this disparate material must be examined according to the reliability of the quotation or summary, and placed in the context of the authors’ interest and biases.
IV.  THE DRAMATIS PERSONAE

It is generally agreed that Thales of MIletus, who is thought to have lived from ca. 624 to 546 BCE, is the earliest Presocratic thinker. (All dates are approximate, though fairly well established in terms of sequence).  Thales was succeeded by two younger Milesian colleagues, Anaximander (ca. 610-546) and Anaximenes (ca. 585-525).  The Milesian pioneers stressed cosmology, a concern that left a lasting effect.  Some see in this concern the remote origins of modern science.  They also illustrated what has been termed Material Monism.  Thales thought that water was the primal element, while Anaximenes assigned that role to air.
Pythagoras, a somewhat shadowy figure, may be placed at ca. 580-ca. 500.  Pythagoreanism was significant in antiquity and long after, because it blended a mystical element with mathematics.
Xenophanes of Colophon, who lived ca. 570-480, was a kind of pro-hippie poet and philosopher who roamed about the Greek lands.  He is best remembered for his iconoclastic views of the gods.
His surviving writings display a skepticism that became more common during the fourth century.  Xenophanes mocked traditional religious views of his time as human projections.  He directed his critique at the polytheistic religious views of earlier Greek poets and of his own contemporaries 
The bold innovator Heraclitus of Ephesus belonged to a new generation, living from ca. 535 to 475.   His witty, often paradoxical utterances of Heraclitus are both beguiling and frustrating. It is generally believed that Heraclitus wrote a single book which supplied the fragments available to us.  According to Diels-Kranz there are 126 authentic fragments.  In his edition Miroslav Marcovich recognizes 122. .
Throughout the surviving passages Heracliitus shows an unwavering self-confidence, bordering on arrogance and even megalomania.  Although all human beings are immersed in the Process (or Logos), very few have the wit to understand  or even recognize their situation.  Heraclitus shows disdain for such predecessors as Hesiod, Pythagoras, and Xenocrates.  In their ignorance they are scarcely better than the common herd.  There are social consequences as well, as when he recommends that the adults of his naive Ephesus should simply hang themselves, so miserable is the mess they have made of the city’s affairs.
Heraclitus’ utterances about opposites rank among his most seminal and challenging observations  First are contraries that stem from different points of view (perspectivism).  For example, “[t[he sea is the purest and most polluted water; to fishes drinkable and bringing safety; to humans undrinkable and destructive.” (fr. 61)  Or, “[t]he most beautiful of apes is ugly in comparison with the human race.” (fr. 82)
Parmenides of Elea (ca. 515-450) is sometimes regarded as a disciple of Xenophanes, though the connection seems tenuous. Seemingly, Parmenides wrote after Heraclitus, and in conscious opposition to him..According to Plato (in his dialogue “Parmenides”), he visited Athens in his sixty-fifth year,  where he encouraged the youthful Socrates. The truth of this account has been doubted. Yet there can be no doubt that Parmenides influenced Plato’s theory of Forms.
Parmenides is commonly viewed as the thinker who contradicted every aspect of our perception of the world by suggesting that change does not occur. This description is surely an oversimplification, and addressing the complexity of Parmenides is a task that continues to engage some of the best minds working on the Presocratics.  He is justly remembered as the founder of the discipline of metaphysics.
Zeno (ca. 490-ca. 430) was the pupil of Parmenides. Zeno is noted for his paradoxes. Melissus, though born on Samos ca. 500 (death date unknown), ranks as the third Eleatic thinker.
Empedocles came from Akragas (ca. 492-432).  He addressed the Milesian preoccupation with his quaternion of earth, air, fire, and water.  For 2000 years this analysis of the basic elements of the universe was to prevail in Western civilization.
A new new note was introduced by Anaxagoras of Clazomenae (ca. 500 – 428), who ranks as the first to bring philosophy to Athens, where he was closely associated with Pericles  Unlike Socrates who was condemned to death on similar charges, Anaxagoras was permitted to retire into exile in Lampsacus.

Responding to the claims of Parmenides which suggested the ultimate impossibility of change, Anaxagoras described the world as a mixture of primary imperishable ingredients, where material variation was never caused by an absolute presence of a particular ingredient, but rather by its relative preponderance over the other ingredients; in his words, "everything is in everything". He introduced the concept Nous (Mind) as an ordering force, which moved and separated out the original mixture, which had been homogeneous, or nearly so.


Democritus of Abdera is something of an outlier, as he was born as late as 450 BCE and died about 370.  He is primarily remembered today for his formulation of the atomic theory of the universe.

His exact contributions are difficult to disentangle from those of his mentor (or associate) Leucippus, as texts often cite them together.. Their speculation on atoms bears more than a passing and partial resemblance to the nineteenth-century understanding of atomic structure.  In consequence many consider Democritus to be the "father of modern science." 

Largely ignored in ancient Athens, Democritus was nevertheless well known to his fellow northern-born philosopher Aristotle,  

Examined more broadly, the Presocratic thinkers fall into four groups.  First, came the early PIONEERS (the Milesians Pythagoras, and Xenophanes).  Then there were the two great INNOVATORS, Heraclitus and Parmenides.  After them came the CONSOLIDATORS (Zeno, Empedocles, Anaxagoras and a few lesser lights).  Finally, there was the CONCLUDER, Democritus, noted for his thorough exposition of the atomic theory.
Not included in this list are the Sophists.  Although there has been a revival of interest in them in recent years, in my view they do not rank either with the Presocratics or with the classical triumvirate of Socrates, Plato, and AristotleAn earlier section raised the issue of a  possible role of Eastern thought (Babylonian and Persian) on the Ionian cities.  It is possible, for example, that Heraclitus’ emphasis on fire reflects Zoroastrian thought. Yet such links remain speculative.
Shared locations favored linkage in successor groups.  Clearly this is the case with the three Milesians, Thales, Anaximander, and Anaximenes.  Somewhat less certain is the role ascribed to Xenophanes in forming the Eleatic school, distinguished by Parmenides, Zeno, and Melissus.
There were also lover pairs, such as Parmenides and Zeno in Elea.  In his youth Zeno had been the eromenos of Parmenides.  Later, as a mature philosopher he faithfully sought to bolster the arguments of his lover with his famous paradoxes.  
Empedocles of Akragas had a less prominent lover, a certain Pausanias, about which little is known.  For his part, Empedocles is known to have discouraged heterosexual copulation, because it tended to disturb the ideal balance of love and strife, the two forces that ruled his universe.  Tacitly, he approved of homosexual unions, for he formed at least one.

V.  GEOGRAPHY 
Where did they come from? Ionia, with the Greek cities in Asia Minor, what is now the Western coast of Turkey was extraordinarily productive.  Miletus provided the earliest thinker, Thales, as well as his successors Anaximander and Anaximenes.  Ephesus was the hometown of Heraclitus, while Colophon produced Xenophanes.
Moving westward, the island of Samos just off the coast of Asia Minor was the homeland of Pythagoras (though his existence remains shadowy) and Melissus.
Finally, the Greek colonies of southern Italy and Sicily were important: Elea in lower Italy, with Parmenides and Zeno; Akragas in Sicily, with Empedocles; and Croton in southern Italy, with Philolaus.
Only with the chronological outlier Democritus (a native of Abdera) does continental Greece become significant.  Of course with Socrates, Plato, and Aristotle, Greece in the narrow geographical sense of the peninsula projecting from the European landmass, become dominant.  The general pattern then is initial concentration on the two extremes, the Greek colonies on the coast of Anatolia and those of Sicily and southern Italy.  Did their status as settler societies foster innovation?  
We have previously noted the possible role of Eastern thought (Babylonian and Persian) on the Ionian cities?  It is possible, for example, that Heraclitus’ emphasis on fire reflects Zoroastrian thought. Yet such links remain speculative.

VI.  UNITY AND PLURALITY

“When we look at the world around us. we seem to see it as made up of a lot of different things. There are trees and stones, houses and squirrels; there are words and flavours, water and grandeur; there are kind actions and major emergencies; birth, deaths, and stereotypes.  All these things seem to be real and observable; all of them (and many others, too) are different kinds of things.  When we divide reality up into chunks like that, we might wonder how many bits there are, and whether we could ever count them.  Are there onlyso many separate things in the world, just this many and no more?  Or if there are no definite natural divisions, perhaps it is really all one?  Could it be all one with no divisions whatever?  The consequences in that case would seem to bve rather strange, as Parmenides and Zeno deftly show.”  (Catherine Osborne, Presocratic Philosophy, Oxford, 2004, p. xvi).

The Founders, the Milesians felt a strong pull towards unity, towards monism.  Thus Thales identified water as the first principle; Anaximenes, air.  The middle figure, Anaximander was a little more cagey, naming only an indefinite stuff as the primordial feature. Heraclitus, their fellow Ionian, singled out fire, though he held that it could morph into water and earth.

The most thoroughgoing monist was Parmenides who held that the perception of plurality was a dangerous illusion.  There is only one thing, perfect, complete and unchangeable.  In this ultramonism, he was followed by Zeno and Melissus.

Empedocles worked out a compromise.  Taking a leaf from the Milesians with their interest in elements, he proposed four “roots”: earth, air, fire, and water.  Governing by two overarching principles, love and strife, these constituent elements could enter into various combinations, producing the multiplicity of our perceived world.  Empedocles also posited a dynamic, temporal dimension, for there was a time when the elements were not as clearly differentiated as they are now; a similar situation will prevail in the future.
Anaxagoras, the adviser of Pericles, posited numerous infinitely divisible components. 
Finally, the atomists Leucippus and Democritus assumed the existence of numerous indivisible components, known as atoms - as well as the void.

VIII.   OPPOSITES  
In everyday speech we are familiar with antonymic pairs.  Some, such as hot and cold, shallow and deep, are a fairly straightforward matter of perception.  Others, such as good and bad, beauty and ugliness, involve value judgments.
Such pairs are sometimes termed binarisms.  The tendency to assemble them is sometimes decried - as by postmodernism - are representing an oversimplification of complex reality. With his doctrine of the mean, Aristotle asserted that the truth sometimes lies between two extremes, in the way, for example, that moderation stands between abstention from alcohol and drunkenness.
To Aristotle is also due the locus classicus of this mode: a table of ten opposed pairs (Metaphysics,986a22):
limit vs. unlimiited
odd vs. even
one vs. plurality
right vs. left
male vs. female
at rest vs. moving
straight vs. crooked
light vs. darkness
good vs. bad
square vs. oblong

Aristotle seems to wish to ascribe this table to the Pythagoreans.  It may have some different origin.  In any case it is a useful list, a kind of summation of several generations of though.
The first thinker whose writings enable us to recover efforts along these lines is the Milesian Anaximander.
Heraclitus famously sought to reformulate the idea with his speculations about the identity of opposites, though in some instances this is only sequential.
Parmenides is generally regarded as a unitary thinker.  However, he does posit two paths of knowledge: the way of truth and the way of opinion.
For his part, Empedocles posited two dominant forces in the universe: love and strife.
Democritus and the atomists may be said to evade the problem by their concept of atoms which are potentially infinite in number.  Yet modern nuclear scientists do recognized opposing positive and negative particles
Cross-cultural parallels have been detected in ancient China and in tribal societies.  The Zoroastrians held that the world was a battleground between the opposing forces of good, headed by Ahura Mazda, and evil, headed by Ahriman.
Nonetheless, the tendency to think in terms of opposites does seem to be particularly characteristic of the early Greek thinkers.

APPENDIX:    KEY WORDS  

Several general themes have emerged in these investigations.  The first is the variability of meaning over time.  In many cases a term (such as logos) begins with a limited, everyday meaning, which then expands.  Because this is a dynamic process, it can be difficult to discern in a given passage whether the older, simpler meaning prevails, or instead the broader, more expansive (and more philosophical) one (e.g. physis in Herclitus). 

ALETHEIA - truth, a key term for Parmenides.
APEIRON - When first used by Anaximander, it meant something like limit, boundary.  I could also be used for a trajectory on a circle; hence the idea of unceasing.  For A. it replaced the primal element (or arche) of water in the system of Thales. This background seems to have led to the meaning of infinite in Aristotle.
ARKHE - the beginning.  Sometimes used for first principle among the Ionian monists.  The source of our terms archaic and archaeology.
DOXA - mere opinion as distinct from ascertained truth.
ELENCHOS - inquiry
ERIS - strife.  Empedocles contrasts with Storge, or love
ESTI - “it is” in Parmenides. Much discussed, it gave rise to the philosophy of Being.
ENANTIA  -  twin, mirror image.  Hence a term for opposites.
The tendency to think in terms of polar opposites is found in many human societies. In some, probably more than most.  At all events the tendency pervades the Presocratics. On need only think of the famous set that Aristotle ascribes to Pythagoras. The tendency is already evident in Thales.  Parmenides shows two: one pertaining to epistemology: aletheia vs. doxa; the other constituting the structure of the universe; Light (Fire?) vs. Night. 
Heraclitus showed the intimate relationship of the opposites, how some phenomena such as the road up + the road down, showed their fusion, while others such as ice vs. water morphed, the one into the other.
Aristotle’s idea of the mean.
There is a heritage in the coincidentia oppositorum of the German mystics (probably going beyond what Heraclitus maintained).  Freud’s held that in the early stages of human language a single word could combine two opposite meanings.
HEN - one
KOSMOS - It originally meant ordering, as in a well-drawn up military formation.  In the sense of ornament, decoration it could also refer to a woman’s well-managed toilette (hence the modern term cosmetics).  The idea of ordering led to the broad sense of the universe, conceived of as ruled by an ordering principle.  Sometimes it meant simply the earth, as distinct from the heavens.  This last sense survives in our term cosmopolitan.
LOGOS - originally word(s), utterance, it came to refer to the ordering principle of the universe.  Both senses may be said to persist in the adjective logikos.
NOOS  - mind.  What is its status? it is more than an abstract noun but less than a personification.
PHYSIS -   Nafure.  In a single instance in Homer, the term is applied to a psychodelic plant.  This suggests that the original meaning was something like “characteristic appearance which permits identification” or perhaps “efficacy.”  The association with the verb phuo, to grow, made it seems suitable in relation to plants.  Yet this connection also facilitated a broader sort of meaning.  Many things grown, and if the world is in some sense alive, then it is universally applicable.  Hence the sense of nature, which is dominant in Plato.  Plato’s later works, such as The Laws, show another shift: at first descriptive, it could be normative (so that something could be “against nature,” even though it is part of nature in the descriptive sense).  The Latin equivalent, natura, has a different set of nuances, stemming from the verb nasci, to be born.
TAXIS - ordering, lineup.